1995 Mazda 626 ABS brake light is on

Hi mazdasam,

Thank you for the donation.

When the ABS indicator light stays on, an error has been detected in the system and it has disabled the ABS system. You would need to retrieve the trouble codes with the aid of appropriate diagnostic equipment to find out what is causing it.

As to the hissing noise when the brake pedal is depressed, it coudl be due to a leaking brake booster. You would need to check it out.